Restructure incomplete or broken "autoconf" implementations

Some plugins with non-zero autoconf exitcodes (it must be zero instead)
deserved a bit of code cleanup for improved readability.

plugins/google/google-rank

@@ -40,14 +40,12 @@
 
 # Auto Configure, Check it word 1 is defined
 if [ "$1" = "autoconf" ]; then
-   if [ "$URL1" != "" ]; then
-      if [ "$WORD1" != "" ]; then
-         echo yes
-         exit 0
-      fi
+   if [ -n "$URL1" ] && [ -n "$WORD1" ]; then
+      echo yes
+   else
+      echo no
    fi
-   echo no
-   exit 1
+   exit 0
 fi
 
 #Configure, loop through each variable defined WORDx URLx dumping it to munin